This invention relates to the application of a therapeutic substance or of a medication to body tissue. In particular, ultrasonic radiation is used in the application of the therapeutic substance.
Medication may be applied to a target body tissue systemically. However, tissue other than the target tissue is also exposed to the medication which may cause harmful side effects. As a result of diffusion of medication into other tissue during systemic application, the concentration of medication that may be applied to the target tissue is limited.
Accordingly, an object of the invention is to provide a method for applying medication so that higher concentrations of medication may be applied to the target tissue.
A further object of the invention is to provide such an application method to minimize side effects in adjacent tissue.
A further object of the invention is to provide a method whereby medication is locally applied to target tissue and selective heat is simultaneously, locally applied to the same target tissue. Application of heat to elevate the temperature of the target tissue to a non-toxic level can enhance the efficacy of certain mediations. Selective delivery of ultrasound radiation can produce the desirable local temperature elevation.
A further object of the invention is to provide such an application method so that timing, duration, and intensity of the application of medication are tailored to suit the needs of an individual patient.
A further object of the invention is to provide an apparatus for applying therapeutic substance to body tissue.